Only a week after our careful study of the Olsen Twins’ trademark Prune faces, clever little Mary-Kate Olsen pulled a fast one on us at last night’s screening for her new film The Wackness: the minx bore actual teeth for photographers, pose after forced pose. And even though it looks like putting on a smile in public is taking every last bit of effort and strength MK's tiny body can muster, the acrobatically trained twin has admittedly perfect chompers. Why she’s been holding back on us remains a mystery, but what doesn’t is where Olsen would rank on yesterday’s roundup of celebrity make-out partners. Her 64-year old Wackness co-star Ben Kingsley clued interested parties in on the talents Mary-Kate’s de-pruned grin is capable of, after the jump.

The Oscar-winning Gandhi star — who would probably rather not have us remind you of his role as a chastity belt expert in D.O.A. Love Guru (especially following a certain co-star's tongue starring in everyone's favorite sex tape du jour) — revealed just how Mary-Kate performed in their very frisky telephone booth make-out scene: "She was completely in charge." While Kingsley isn't earning any points in the specificity department, we're going to give the new smiling version of MK the benefit of the doubt and assume the 22-year old's ability to "take charge" while playing tongue twister with someone more than 40 years her senior is yet another new talent she can add to her resume.